Hey all,

Back at the end of August we picked up a complete basket case of a 2010 Mini base (or as I guess its known around here as a R56 N12 Justa?) with 126K on it for my daughters first car at a good price as a learning project. We had to limp it home as it had NO brakes in the rear (caliper piston on rotor) and no exhaust (flex joint busted off) and was very much due for the timing chain (with codes to back that up)


Together, we did many things to it to get it back on the road all while teaching the kid about how cars work, but the pertinent things to this issue are:

- Replaced Timing Chain & Tensioners and reset adaptations via Schwaben tool from @ECS Tuning
- Replaced Oil Filler Cap (o-ring was shot)
- New exhaust flex joint
- Replaced exhaust VANOS solenoid
- Replaced intake VANOS solenoid


After we did all the above, many of the codes cleared, but we were still getting the P300 / P301 / P302 / P303 / P304 random misfire errors on all cylinders as well as a P2197 - System too lean at idle bank 1. The car had a very erratic/sometimes violent idle, and it would sometimes stall/die when stopping and coming to idle which it wasn't doing when we limped it home from purchasing. So, I did the following:

- Replaced all 4 coil packs
- Installed new NGK Iridium Spark Plugs


The misfire codes went away and the idle was much better, but obviously we were still getting the P2197 - too lean at bank 1 message and the idle was randomly hunting and stalling sometimes but the car ran great at speed. I sprayed starting fluid every where I could think of but nothing changed. Out of desperation:

- Replaced PCV Valve (it was good, but after pulling the cover the tabs cracked so I replaced it anyways)
- Replaced PCV/Crankcase hose (found it had a crack in it under the intake manifold and was VERY brittle)


Now, the idle is solid, no more crazy surging and hunting. However, when coming to a stop the car stumbles quite a bit trying to come to an idle and then levels out. In my testing, it seemed like it would get better if I put it in park after coming to a complete stop, but that also may have been it leveling out on its own. It also seemed like coming to a slow stop would be smoother idle than an abrupt stop. This is the first Mini I have ever worked on, or even seen up close for that matter, so I am not sure where to head next. It seems like a vacuum leak or potential brake booster issue. However, once the idle levels out pumping the brakes has zero effect on the idle. I have searched quite a bit and haven't really found anything. Maybe I am not using the right keywords or something, or maybe I am heading down the wrong road and its a fuel issue with the injectors, filter, or either of the pumps? IDK.




If anyone has any insight or thoughts both me and my kid would be grateful. We have put two months and over two grand into this thing, and I just really want it to be a rock solid vehicle for her when she leaves to another state for college next fall.